1. Field of the Invention
The inventive concept relates to a hard disk drive, and more particularly, to the structure of a latch device of a hard disk drive.
2. Description of the Related Art
Hard disk drives (HDDs) are one of information storage devices. The HDD records data on a disk, or reads the data stored in the disk, by using a magnetic head. In the HDD, while flying at a predetermined height above a recording surface of a rotating disk, the magnetic head is moved by an actuator arm to a desired position to perform the above functions.
When the HDD is not in operation, that is, the rotation of a disk is stopped, the magnetic head is parked at a position out of the recording surface of the disk to prevent the magnetic head from colliding against the recording surface of the disk. The parking system of the magnetic head may include a contact start stop (CSS) method and a ramp loading method. In the CSS method, a parking zone where data is not recorded is provided at the inner circumferential side of the disk and the magnetic head is parked in the parking zone by contacting the parking zone. In the ramp loading method, a ramp is installed outside the disk and the magnetic head is parked on the ramp.
When the magnetic head is parked in the parking zone of a disk or on the ramp as described above, an external shock or vibration is applied to the HDD so that the actuator arm is freely moved and thus the magnetic head escapes from the parking zone or ramp to move over the recording surface of the disk. In this case, the magnetic head contacts the recording surface of the disk so that the magnetic head or the recording surface of the disk may be damaged. Thus, when the rotation of the disk is stopped and the magnetic head is parked in the parking zone or on the ramp, there is a need to latch the actuator arm at the parking position not to be freely rotated. To this end, a variety of latch devices are provided in the HDD.
A latch device includes a latch lever pivotably installed on a base of the HDD to confine a rear end portion of the actuator arm at the parking position. The latch lever is arranged between the base and a top yoke of a voice coil motor (VCM). A predetermined clearance (hereinafter, referred to as the upper clearance of the latch lever) for smooth rotation of the latch lever exists between the latch lever and the top yoke.
Although the upper clearance of the latch lever is necessary for the smooth rotation of the latch lever, the latch lever may be shaken in a vertical direction or vibrate when an external shock or vibration is applied to the HDD. As the latch lever is shaken in a vertical direction or vibrates, the latch lever collides against the base and/or the top yoke. An internal shock caused by the above collision may generate an error during a recording operation or reading operation of the HDD.